塔河油田注氮气—水系统压力预测

发布时间：2018-09-08 20:46

【摘要】：塔河油田在前期注水开发后,由于其特殊的缝洞单元结构,形成了注入水无法波及的“阁楼油”。针对这一现象,油田实行了单井注氮气试验,但是在前期试验中发现,由于各缝洞单元储层结构、发育程度以及连通程度的不同,不同单井注气时井底压力响应曲线形态各异,且不同缝洞单元注气量大不相同,油田在进行单井注气量、注气压力以及焖井时间等参数设计时,缺乏合理的理论指导。针对这一问题,本文提出了一套缝洞型储层注氮气-水井筒、储层系统压力预测模型的建立方法。流体从井筒经井周裂缝储集带注入溶洞,其中在垂直井筒中的流动为管流,在井周裂缝储集带中为渗流,进入溶洞后为自由流动。根据这一流动原理,将单井注氮气-水系统分为两部分：井筒部分和储层部分,其中储层部分包括井周储集带和溶洞,分别建立各部分在注氮气-水时的压力预测模型。在井筒系统方面,对井筒气水两相流动漂移模型进行了改进,使其适用于垂直井筒向下注入气水时的井筒压降计算,漂移模型充分考虑了两相流界面效应,可用于不同注入气水比的单井井筒压力分布计算。在储层压力方面,基于塔河油田的储集体类型和生产动态特征,建立了单井注入过程的物理模型,根据物质平衡原理,推导出注气采油过程中溶洞内压力与注入流体体积的关系,在此基础上,结合质量守恒定律、产能方程,分别建立了纯氮气注入、氮气-水混合注入时的注入过程和焖井过程储层压力模型,并对模型进行了无因次化处理,最后分析了井所在储层类型、井筒周围导流能力和井口注入速度对井底压力的影响。通过实例验证,说明了井筒、储层压力预测模型具有较高的有效性和实用性。单井注入系统压力预测模型的建立,为塔河油田注氮气-水参数优化分析和制定合理的工作制度提供了理论基础。
[Abstract]:The loft oil which can not be affected by injected water is formed because of its special fracture-cavity unit structure after the earlier water injection development in Tahe Oilfield. In view of this phenomenon, the single well nitrogen injection test was carried out in the oilfield, but in the previous experiment, it was found that because of the different reservoir structure, development degree and connectivity degree of each fracture and cavity unit, the bottom hole pressure response curve of different single well injection was different. The gas injection rate of different fracture-cavity units is very different, and the design of single well gas injection rate, gas injection pressure and braising time is lack of reasonable theoretical guidance. In order to solve this problem, this paper presents a set of methods for predicting the pressure of the reservoir system by injecting nitrogen gas and water into the wellbore. The fluid is injected into the cavern from the wellbore through the fracture zone around the well, in which the flow in the vertical wellbore is pipe flow, the flow in the fracture zone around the well is percolation, and the flow is free after entering the cavern. According to this flow principle, the single well injection nitrogen gas-water system is divided into two parts: the wellbore part and the reservoir part, in which the reservoir part includes the reservoir zone and the cavern around the well, and the pressure prediction models of each part during the injection of nitrogen gas and water are established respectively. In the aspect of wellbore system, the two-phase drift model of gas-water flow in wellbore is improved, which is suitable for the calculation of wellbore pressure drop when the vertical wellbore is injected with gas and water down. The drift model takes full account of the effect of two-phase flow interface. It can be used to calculate the wellbore pressure distribution of single well with different injection gas / water ratio. In terms of reservoir pressure, based on the reservoir types and production dynamic characteristics of Tahe Oilfield, a physical model of single well injection process is established, and according to the principle of material balance, The relationship between the pressure in the cavern and the volume of the injected fluid in the process of gas injection is deduced. On the basis of this, the pure nitrogen injection is established by combining the law of conservation of mass and the equation of productivity. The reservoir pressure model during the mixed injection of nitrogen and water, and the dimensionless treatment of the model are carried out. Finally, the effects of the reservoir type, the flow conductivity around the wellbore and the injection velocity of the wellhead on the bottom hole pressure are analyzed. The example shows that the well bore and reservoir pressure prediction model is effective and practical. The establishment of pressure prediction model for single well injection system provides a theoretical basis for optimizing the parameters of nitrogen injection and water injection in Tahe Oilfield and making a reasonable working system.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357

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